<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="resource/js/vue.js"></script>
</head>
<body>
<div id="app">
    <select v-model="selected">
        <option value="a">A</option>
        <option value="b">B</option>
        <option value="c">C</option>
    </select>
    <span>Selected {{selected}}</span>
</div>

<script>
    new Vue({
        el:'#app',
        data:{
            selected: 'c'
        }
    })
</script>
</body>
</html>